ES2370648T3 - ABSORBENT TEXTILE PRODUCT. - Google Patents

Abstract

The present invention relates to an absorbent textile product consisting of 100% synthetic fibers, particularly suitable for household cleaning and personal hygiene purposes.

Description

Absorbent textile product

The present invention relates to the field of nonwoven textile products and is applied to the production of absorbent fabrics for household cleaning and personal hygiene purposes.

Absorbent textile products are normally made from cellulose-based raw materials, such as viscose, cotton and the like, which are provided, "naturally" with more or less absorbent capacity. However, these raw materials are known to be expensive. In order to reduce the cost of finished products, efforts have been made to obtain absorbent fabrics of synthetic fibers; In this case, however, in order to obtain a finished absorbent product, a treatment with specific chemical additives that can provide a "wettable" product is required. This type of treatment is not permanent, since this fabric tends to become water resistant again after being wetted with water and drained for the first time. Accordingly, the use of these textile products is restricted to disposable applications. On the other hand, in addition to having a common language, these procedures only partially improve wettability, but not other features such as the general softness of the tissue.

US 4,818,594 discloses a nonwoven fabric produced by blow spinning of a melt or a solution of a polymeric material that can be spun to give fibers and filaments that are transformed into a nonwoven fabric by spinning by depositing them in a receiving medium. . The non-woven fabric is consolidated by means of water jets and during or immediately after this consolidation by water jets a surfactant is applied as a wetting agent. The non-woven fabric is then dried.

WO 03/000975 describes a bar of soap made from a nonwoven web that preferably comprises cut fibers made of 100% polyester. In order to impart elastic characteristics to the nonwoven fabric, a polymeric binder composition is uniformly applied to the nonwoven fabric. The binder is preferably acrylic binder. The fabric is also treated with a wetting agent (Tween 20).

However, none of the above documents describe a non-woven fabric as defined in the characterizing part of claim 1.

An object of the present invention is to provide a novel textile product consisting of synthetic fibers, which is capable of maintaining a high absorbent power after use, having been treated with a suitable wetting agent.

A further object of the invention is to provide a non-woven fabric with improved wettability, which has improved characteristics of absorption time, amount of absorbed liquid, ability to retain absorbed liquid and general softness.

Now, the applicant has found that, contrary to hydroentangled textile products made of synthetic fibers of the prior art, the treatment with wetting additives which is carried out on nonwoven fabrics interwoven by hydroentangling as defined in claim 1, surprisingly gives to the product good absorption characteristics, which are associated with an increase in the general softness characteristic of the nonwoven fabric interwoven by hydroentangling. These good characteristics persist in the product throughout the entire use cycle.

Similar results have been obtained by carrying out the wetting treatment directly after the manufacture of the nonwoven fabric, rather than on the finished fabric, in particular between the hydro-entangling stage and the final winding of the product.

Accordingly, an object of the present invention is a nonwoven textile product interwoven by jets of pressurized water as defined in claim 1 consisting of hydroentangled synthetic fibers that are made permeable through a wetting treatment.

A further object of the invention is the process for preparing said textile product.

The textile product of the invention can be applied mainly in the field of household cleaning and personal hygiene. In particular, it is adapted to the manufacture of cloths, rags and similar fabrics for cleaning any surface, wipes, baby wipes, etc.

The process for preparing this non-woven fabric is carried out in accordance with the technique known as "interlacing by jets of water under pressure", followed by hydro-entangling of the fibers, preferably through jets of high-pressure water; then the free water that is trapped between the fibers is removed by drying.

The wetting treatment can also be carried out both in nonwovens interwoven by jets of pressurized water with previously existing hydroentangling, and after processing thereof. The wetting treatment can also be carried out on the nonwoven raw fibers that have been previously treated with wetting agents.

Preferably, the wetting treatment is carried out after hydro-entangling and before oven drying.

Wetting additives are those commonly used in the technical field, such as ionic, cationic or anionic surfactants, preferably EUCAROL® available from LAMBERTI S.p.A. In the course of conducting tests, this additive was highly effective in terms of providing absorption capacity to the final product with a low dosage. In fact, the addition of a low dosage of additives leads to highly superior products compared to products obtained with high dosages, as will be discussed in detail below.

The treatment procedure can be selected from those used in common practice. There are, among others:

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spraying: the product mixture will be sprayed on the fibers in one stage along the manufacturing line that is between the hydro-entangling and final winding stages;

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laminate: the product mixture will be applied by a contact roller dispersing the products on the surface of the nonwoven product interwoven by water jets;

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stamping: same as laminate, but with a stamping machine;

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impregnation; the nonwoven interwoven by jets of pressurized water, either already consolidated or in an intermediate stage, is immersed in a mixture of selected products, then the excess amount is drained by means of a roller or similar systems;

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Foam bonding: a mixture of selected products is treated until it is in a foamed physical state and then applied by conventional techniques (for example, screw filler, blade coating, etc.).

The dosage of the wetting additive changes depending on the fibers being used, the characteristics of nonwovens interwoven by jets of pressurized water (density, fiber distribution, etc.) and desired level of absorption (meaning the amount of water absorbed, retained and absorption time, capillarity).

The impregnation followed by a pressure extraction roller is the preferred treatment procedure, which is advantageous with respect to the other processes because it allows the wetting additive to more evenly spread throughout all the fiber parts, even within the nonwoven. In this case, the concentration in the bath will range between 1 and 10 g / l, preferably 1 and 5 g / l. For example, if a solution with an additive concentration of 1 g / l is used, the absorption of the nonwoven fabric being 100%, an amount of 1% of absorbed additive will be obtained.

The nonwoven fibers entwined by jets of pressurized water, after hydro-entangling, are passed to a bath of moisturizing additive in the concentrations described above, then sent to the pressure extraction roller and then to the drying oven.

The pressure extraction roller is adjusted so that the extraction is calibrated, that is to say the pressure will be such that a very small amount of liquid remains, in order to make the stay in the drying oven as short as possible. At the same time, the pressure should not be so high as to calender the nonwoven entwined by jets of pressurized water, which would result in modifying the architecture of the nonwoven fabric. After a series of tests, it has been observed that the best results are obtained with pressure values that vary between 4 and 8 bar, preferably 6 bar, when applied to a nonwoven interwoven by jets of water under pressure immersed in a solution of humectant additive at the previous concentrations.

After the pressure extraction roller, the nonwoven fabric is sent to the drying oven. The temperature inside the oven will depend on the speed at which the product passes through it and is adjusted so that complete evaporation inside the oven is ensured. For example, if a product with a weight of 55 g / m2 is produced at 150 m / min, the temperature inside the oven is adjusted to approximately 120 ° C for complete evaporation of water.

Synthetic fibers that can be used in the preparation of the present textile products are for example fibers of a material selected from the group consisting of polyester, polypropylene, polyamide, acrylic and mixtures thereof, preferably 100% polyester or polypropylene. 100%

Not all commercially available synthetic fibers can be used for the purposes of the invention. In fact, after a series of tests, it has been found that the quality of the final product, particularly in terms of softness and absorption capacity, depends on the percentage of additives provided in the starting fibers.

Various types of additives are added to synthetic fibers by manufacturers, such as: lubricant additives to give the fibers softness and ease of processing; antistatic additives to avoid harmful electrostatic currents that can degrade the product, or in the worst case, reduce the productivity of the machine; hydrophilic additives to impart minimum affinity to water, antifoam additives to prevent foaming after the hydro-entangling stage.

Synthetic fibers that can be used for the purposes of the present invention will have a very low percentage of starting additives. For example, a percentage that varies from <0.1% to 0.2%. Examples of these fibers are 100% polyether fibers purchased from Dupont, Montefibre, Hochst, Catalana, etc.

Preferably, the non-woven fabric of the invention, in addition to being treated with wetting additives, is also treated with antifoaming additives in order to adjust the surface tension of the wetting agent solution.

Examples of such antifoaming agents are silicone based additives. The preferred antifoam agent is HANSA SP® available from HANSA spa.

The antifoam agent can be applied to the nonwoven fabric using the various treatment procedures described above. Advantageously, the antifoaming agent is applied by impregnation, simultaneously with the wetting agent, that is to say a single bath is prepared containing both the wetting agent and the antifoaming additive. The antifoam agent solution that is advantageously used for the product of the invention has a concentration ranging from 1 to 7 g / l, preferably about 2 g / l.

The antifoaming agent serves to adjust the surface tension of the wetting agent, that is the ability to generate foam after application. Hydrophilic additives are also available, which are ineffective even if they are poorly foaming and therefore require use in high dosages. As already discussed above, both the starting additives and the hydrophilic and defoaming additives that are added after processing damage the final quality of the product when added in high dosages.

Therefore, the best choice is that suggested by the present invention, that is, using fibers with low amounts of starting additives, to which small amounts of wetting agent with high foaming capacity are applied and simultaneously, also amounts reduced from an antifoam additive.

The product of the invention comprises 3 to 9 cardial veils. With a number of bands greater than one, a more isotropic textile structure is ensured and accordingly a maximum spatial arrangement of the fibers, which translates into a maximum fiber-water contact surface. Therefore, water droplets are absorbed by the structure within the small spaces that result from the random distribution of the fibers. The absorption capacity of the finished product is guaranteed by the arrangement of several bands, together with the application of the wetting agent.

The textile product thus obtained typically has a weight / surface ratio that varies between 30 and 150 g / m2.

The textile product obtained according to the invention is highly hydrophilic, is provided with considerable absorption power and with considerable softness and good handling property, which also persists after the first use. This is contrary to non-hydroentangled textile products made with synthetic fibers, of the prior art.

In particular, the product of the invention has a lower absorption time, a greater capacity to retain it, as well as a greater overall smoothness.

The textile product of the invention has considerable versatility of use and can generally be applied in the fields of household cleaning and personal hygiene. It can be used in the preparation of any type of cloth for drying surfaces, such as cloths, rags and similar fibers to clean floors and other household surfaces, as well as wipes, baby wipes, etc.

In the course of testing, the cloth prepared as described above exhibited considerable absorption power, which has remained quite unchanged after use (Table 1).

Particularly, after having been subjected to the wetting treatment according to the invention, the absorption power of the product can be compared with that of a product consisting of 50% viscose and 50% polyester and remains elevated in the product during the use cycle This result is even more surprising considering that the comparative product contains 50% viscose, which is a naturally hydrophilic fiber.

Table 1

SAMPLE

DRY WEIGHT / g (m2) WET WEIGHT / g (m2) ABSORPTION (%)

100% polyester

Untreated

51 399 682

Treated 1 g / l

48 411 756

Treated 2 g / l

47 445 847

Treated 5 g / l

48 473 885

VP

Untreated

51 609 1094

VP = 50% viscose and 50% cellulose 5 The evaluation of the absorption power can be carried out in accordance with the EDANA 10.4-02 ABSORPTION standard.

In addition, in comparative tests, the product of the invention, at the same thickness, has been shown to have improved resistance to longitudinal and transverse load and longitudinal and transverse elongation properties

10 improved when compared with a cloth consisting of a mixture of 50% viscose and 50% polyester, as illustrated in Tables 2 and 3.

Table 2

Akena P40

VP 40

Thickness (mm)

0, 57 0.56

Load L / T (N)

70/24 46 / 11.5

Elongation L / T (%)

52/160 38/137

Table 3

Akena P50

VP 50

Thickness (mm)

0, 62 0, 58

Load L / T (N)

115/31 64/16

Elongation L / T (%)

49/155 38/135

Akena P40 and P50 = cloth of the invention of 100% polyester having a weight of 40 g / m2 and 50 g / m2, respectively.

VP40 and VP50 = comparative cloth of 50% viscose and 50% polyester that have a weight of 40 g / m2 and 50 g / m2, respectively. 25 L / T = longitudinal and transverse.

Claims (16)

one.

A textile product of nonwoven fabric interwoven by jets of pressurized water consisting of synthetic fibers that are hydro-entangled and are made permeable by means of a moisturizing treatment characterized in that the product comprises 3 to 9 veils of card.

2.

The product according to claim 1, wherein said fibers are fibers of a material selected from the group consisting of polyester, polypropylene, polyamide, acrylic and mixtures thereof.

3.

The product according to claims 1-2, which has a weight ranging between 30 and 150 g / m2.

Four.

The product according to claims 1-3, in the form of a cloth, cloth or other cloth for drying surfaces, wipes, baby wipes.

5.

The product according to any one of claims 1 to 4, consisting of synthetic fibers of 100% polyester or 100% polypropylene.

6.

A process for preparing the textile product as described in claims 1-5, characterized in that a fabric interwoven by water jets under hydro-entangled pressure in the final state or a fabric interwoven by water jets under pressure is subjected to a wetting treatment. It has already been hydroentangled and has not yet dried.

7.

The process according to claim 6, wherein the starting fibers are 100% polyester or 100% polypropylene and with a starting additive content of <0.1% to 0.2%.

8.

The process according to any one of claims 6 to 7, wherein the wetting treatment is carried out by means of a selected technique of spraying, laminating, stamping, impregnation, foam application.

9.

The process according to any of claims 6 to 8, wherein said wetting agent is selected from cationic, anionic or non-ionic surfactants.

10.

The process according to any of claims 6 to 9, wherein the concentration of the wetting agent solution varies between 1 and 10 g / l, preferably 1 and 5 g / l.

eleven.

The process according to any of claims 6 to 10, comprising a step of treatment with an antifoam additive.

12.

The method according to claim 11, wherein said antifoam treatment is carried out simultaneously with the wetting treatment.

13.

The method according to claim 11 or 12, wherein said antifoam agent is a silicone based antifoam agent.

14.

The process according to any of claims 11 to 13, wherein said antifoam treatment is carried out by impregnation using a solution of the antifoam agent in a concentration ranging from 1 to 7 g / l, preferably about 2 g / l.

fifteen.

Uses of the textile product described in claims 1-5, for the manufacture of products used for household cleaning and personal hygiene purposes.

16.

Use according to claim 15, wherein said product is selected from a cloth, cloth or other cloth to dry surfaces, wipes, baby wipes.